Scientists have discovered a new technology to diagnose Alzheimer's disease from blood samples long before symptoms appear.
The new method uses synthetic molecules to seek out and identify disease-specific antibodies and could be a big help in diagnosing Parkinson's disease and immune system-related diseases like multiple sclerosis and lupus, the researchers predict.
"If we can find a way to detect the disease in its earliest stages - before cognitive impairment begins - we might be able to stop it in its tracks by developing new treatment strategies," said Dr. Dwight German.
AD patients exhibit immune system activation and neurodegeneration in several brain regions so researchers hypothesized that there may be numerous antibodies in the serum of affected patients that are specific to the disease and can serve as a biomarker.
The new study uses synthetic molecules (peptoids), which can be modified easily and can be produced quickly in relatively large amounts at lower cost.
The technology behind this discovery is essentially an immune-system reader, which is designed to pick out antibodies without knowing in advance which ones to look for.
The particular peptoids that retained more antibodies from the blood samples of the diseased animals were identified as potential agents for capturing diagnostically useful molecules.
Three peptoids were identified that captured six times the IgG antibody levels in all of the Alzheimer's patients when compared to the control group or to the Parkinson's patients.
Two of the peptoids were found to bind the same IgG antibody, while the third was shown to bind to different antibodies - meaning there are at least two candidate biomarkers for AD.
Using an additional set of 16 normal control subjects and 10 subjects at the very early state of AD, the three candidate biomarkers identified AD with 90 percent accuracy.
"The results of this study, though preliminary, show great potential for becoming a landmark," said German.
The study is published in the Jan. 7 edition of Cell.